Kids and pets

SAN FRANCISCO -- Contrary to many parents' instinct, infants who grow up with cats or dogs may be less likely to suffer from allergies and asthma later in life, preliminary research suggests.

"Traditionally, most people have thought that increased exposure to these allergens leads to more allergies," said Dr. Darryl Zeldin of the National Institute of Environmental Health Sciences. "But I think those conclusions are being re-evaluated."

Most research has focused on how to reduce allergy sufferers' exposure to household irritants, such as dust mites and pet dander.

But new evidence suggests that exposure to pets early in life might actually help the body build defenses against allergies and even asthma.

"Kids exposed to animals seemed to be better off," said Christine C. Johnson, a researcher with the Henry Ford Health System in Detroit who conducted one of several studies on the effects of pet exposure during infancy.

Johnson's study, involving researchers in Georgia and Michigan, found that exposure to two or more cats and dogs at 1 year of age made children less susceptible to other allergy-inducing substances by the time they turned 7, and that the exposure even improved some boys' lung function.

The study tracked 833 children, testing 473 of them after six or seven years to determine how exposure to pets when they were infants influenced their tolerance to allergens. The results were presented at an American Thoracic Society conference last month.

Johnson and other researchers still caution that the subject remains complex.

"Are we proposing that if every house in the county had cats, everything would be all right? I doubt it," said Dr. Thomas Platts-Mills, a University of Virginia allergy research specialist.